The presidents of Russia and Iran have met in the Azerbaijani capital, Baku, hoping to mend a breakdown in relations.

Dmitry Medvedev of Russia and his Iranian counterpart, Mahmud Ahmadinejad, held bilateral talks on the sidelines of a summit of leaders of the five states littoral to the Caspian Sea.

Neither Medvedev nor Ahmadinejad has commented publicly on the results of their meeting yet.

But Interfax news agency quoted Medvedev's top foreign policy aide, Sergei Prikhodko, as saying the conversation was "of a completely open nature," and that neither side "avoided unpleasant questions."

Prikhodko said the meeting focused on "the development of relations with Iran," with which he said Russia is "keen to maintain trade and economic ties."

But he also quoted Medvedev as stressing at the talks the importance of Iran having a peaceful nuclear program.

Russia has been viewed as an Iranian ally after years in which it has blocked or diluted international sanctions over Tehran's controversial nuclear program.

But bilateral ties have been strained over a number of issues.

Russia has backed a series of United Nations Security Council sanctions against the Islamic republic, while Medvedev himself has voiced a growing sense of frustration with Tehran's persistent nuclear ambitions.

A nuclear reactor at Bushehr in southern Iran was completed by Russian contractors only in August after years of delays, which Moscow explained by citing payment difficulties but which were denounced as mere foot-dragging by Tehran.

But arguably the biggest irritant came in September, when Moscow officially dropped an estimated $800 million contract to sell Iran its S-300 long-range antiaircraft missiles.

Iran showed its displeasure, with Ahmadinejad accusing Russia this month of selling out "to our enemies" -- referring to the United States.

Ready For Negotiations

But Tehran appealed for a return to stronger ties with Moscow on November 17, when a Foreign Ministry spokesman insisted that the two countries had "an enormous potential for political, economic, and technological cooperation."

Speaking to Russia Today television, Ramin Mehmanparast said Tehran believed Western powers had been trying to hamper the longtime cooperation between Iran and Russia.

The UN Security Council has slapped four sets of sanctions on Iran over its refusal to suspend uranium-enrichment activities. And in recent months, the United States, as well as the European Union and Japan, approved new unilateral economic sanctions against Iran.

Iran and six world powers -- Britain, France, Germany, the United States, Russia, and China -- are set to resume talks on Iran's nuclear program on December 5, but the sides are yet to agree on a venue and an agenda.

The talks are meant to allay Western concerns Iran's nuclear program is aimed at making weapons, something Iran denies.

Ahmadinejad told a press conference in Baku earlier in the day that the Islamic republic was "ready for negotiations" over its nuclear program, but warned that world powers should stop "putting pressure" on and "threatening" Iran if talks are to be successful.

"The U.S. government doesn't have economic ties with us. It issues a sanction resolution. What is its meaning? It means that it wants to sanction others," Ahmadinejad said.

"We believe that the language of sanctions belongs to 30 years ago. In a world where there is competition for free trade, sanctions fail. Imposing sanctions on Iran fails. Iran is a very big powerful historical country."

Caspian Summit

The Caspian summit itself, the third such gathering that also includes Azerbaijan, Kazakhstan, and Turkmenistan, was not expected to make much progress on defining the legal status of the world's largest inland body of water.

Previous talks on the issue have ended with little progress, while the former Soviet Caspian littoral states have gone ahead and started developing their sectors of the sea.

If the Caspian is defined as a sea, the countries are free to develop their national sector as they wish and keep the profits they receive from it. If the Caspian is a lake, profits from selling the hydrocarbon wealth should be split equally between the five.

Security was also expected to be an important topic at today's talks.

All five countries recognize that narcotics, illegal weapons, and extremists and their supplies are crossing the Caspian Sea in increasingly larger numbers.

In a separate development, the Azerbaijani presidential administration said in a statement that President Ilham Aliyev and Ahmadinejad "expressed confidence in the further development of bilateral relations" during talks in Baku on November 17.

Iran's Fars news agency reported that the two sides signed two memoranda of understanding aimed at expanding economic cooperation in the transportation, oil, and gas fields.